Project owner: Auvergne-Rhône-Alpes region.
The need to avoid vibration – Smooth compaction
Issue of waterproofing linked to flooding and the infiltration of rainwater - Use of permeable BioKlair®
Difficulty of access (no motor vehicles allowed) – use of “small” construction machinery (Sambrons-powered mini paver), manual application for observatory access routes
Integration into the landscape – BioKlair® formulated with local light-grey aggregates (Chênes quarry approximately 30 km away).
The decision was made to use the eco-friendly and permeable BioKlair® mix, combining local aggregates and a light-coloured plant-based binder, designed and manufactured by Eiffage Route (granular size 0/6 mm over a thickness of approximately 4.5 cm for a total tonnage of 350 T of mix applied).
Specially adapted to cycle paths and other soft mobility solutions, this plant-based binder produced at a lower temperature is made from co-products of the forestry and paper industry, combined with a synthetic resin. BioKlair® improves water management because it is designed to be permeable, allowing runoff water to infiltrate the soil (e.g. heavy rains and flood waters). In addition, Bioklair® reduces the temperature of the road surface during periods of high heat, effectively preventing urban heat islands (UHI). Its light-coloured aggregates allow it to better reflect and diffuse solar energy (Albedo effect), compared to a conventional bitumen asphalt.
The work was carried out over a two-day period at the end of November, with an ambient temperature of between 4° and 10°C.
The mix proved very easy to work with, presenting good overall appearance and a very high level of permeability. The finish obtained (light brown) was in line with the objective of integrating the project into the surrounding environment (blending in with the natural earth footpaths). Since it was applied, the mix has lightened up as a result of the effects of UV rays (a natural phenomenon for a light-coloured mix bringing out the natural color of the aggregates).